Hvdc modular platform design

ABSTRACT

A modular HVDC platform and a method for constructing the same are disclosed herein. The modular HVDC platform has a topside disposed on a structural jacket. The topside includes a first rectifier module, a second rectifier module, and a utility module. The first and second rectifier modules have equipment for converting AC power to DC power disposed therein. The utility module contains equipment for supporting the operations of the rectifier modules. Each of the rectifier modules and the utility modules can be fabricated and commissioned onshore prior to installation on the structural jacket at an offshore location.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. provisional patent applicationSer. No. 62/510,426, filed May 24, 2017, which is herein incorporated byreference.

BACKGROUND Field

Embodiments of the present disclosure generally relate to offshoreplatforms for wind energy generation. More specifically, the disclosurerelates to a modular HVDC platform for converting AC power to DC power.

Description of the Related Art

The rapid growth of the wind power generation industry has resulted inthe development of large wind turbines grouped in clusters that cangenerate large amounts of power. These large wind turbines are commonlyinstalled far from shore at offshore locations which presents manychallenges for transmitting the generated power back onshore. Windturbines produce power in alternating current (AC). AC power has largelosses in power over long transmission distances. Thus, AC powerinstallations are generally installed close to shore to minimize thelosses, or supplemented by installing costly “boosting stations” totransmit the generated AC power over long distances. In order toovercome the losses that exist in AC power transmission and reduce thesize of the transmitting cables, the industry has moved to grouping thewind farm power into larger power generating sites, typically 900 MW,and then converting the power to Direct Current (DC). DC power does notexhibit the power losses associated with AC power over long transmissiondistances. DC power is used to transmit the power to a land-basedinverter station where the DC power is converted back to AC power forincorporation in a distribution system.

Due to the large generating capacity associated with current windgeneration facilities, the conversion equipment needed by the HVDCrequires a large footprint. For example, the converting equipmentdissipates a large amount of heat directly to the ambient air so a largesystem is needed to handle the heat loads. Also, the high voltages ofconversation equipment have a potential to arc from one location toanother within the HVDC platform, so sufficient distance betweencomponents and inert atmospheres are required to prevent such arcing.Such space requirements and weight of the associated equipment has ledto increasingly large and heavy topsides of the converting platforms,typically in excess of 20,000 metric tons, far exceeding those used inoil and gas platforms. Still further, the design and construction ofsuch platforms has proved problematic and prohibitively expensive.

Therefore, there is a need for an improved HVDC platform design.

SUMMARY

The present disclosure generally relates to offshore platforms for windenergy generation. More specifically, the disclosure relates to amodular HVDC platform for converting AC power to DC power.

In one aspect, an offshore platform for power generation comprises astructural jacket, a utility module disposed on the structural jacket,the utility module disposed in a first housing, and one or morerectifier modules disposed on the structural jacket adjacent to theutility module. Each of the one or more rectifier modules is disposed ina respective second housing, and each rectifier module comprisesequipment for converting AC power to DC power.

In another aspect, a system for wind energy generation comprises anoffshore platform comprising a structural jacket and a topside, whereinthe topside comprises a plurality of modular sections position on amodule support frame. The system also includes a first plurality ofrectifiers disposed in a first module of the plurality of modularsections, the first module positioned within a first housing; and asecond plurality of rectifiers disposed in a second module of theplurality of modular sections, the second module positioned within asecond housing. The system also includes a third module of the pluralityof the modular sections, wherein the third module is a utility moduleconfigured to support the operations of the first module and the secondmodule, the third module positioned within a third housing.

In another aspect, a method of constructing an offshore platformcomprises installing a substructure at an offshore location, installinga module support frame on the substructure, and installing a firstmodule of a topside on the module support frame. The first modulecomprises pre-installed equipment for converting AC power to DC power.The method also includes installing a second module of the topside onthe module support frame, the second module comprising pre-installedequipment for converting AC power to DC power, and coupling the firstmodule and the second module.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlyexemplary embodiments and are therefore not to be considered limiting ofits scope, as the disclosure may admit to other equally effectiveembodiments.

FIG. 1 is an illustration of an exemplary offshore wind generation site.

FIG. 2 is an isometric view an exemplary modular HVDC platform accordingto one embodiment.

FIG. 3 is a plan view of an exemplary modular HVDC platform according toone embodiment.

FIG. 4 is a schematic energy flow of an HVDC system according to oneembodiment.

FIG. 5 is a flowchart of a method of constructing a platform accordingto one embodiment.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

The present disclosure relates to a modular HVDC platform and a methodof constructing the same. The modular HVDC platform has a topsidedisposed on a structural jacket. The topside includes a first rectifiermodule, a second rectifier module, and a utility module. The first andsecond rectifier modules have equipment for converting AC power to DCpower disposed therein. The utility module contains equipment forsupporting the operations of the rectifier modules. Each of therectifier modules and the utility modules can be fabricated andcommissioned onshore prior to installation on the structural jacket atan offshore location.

FIG. 1 is an example of a wind generating facility 100 at an offshorelocation. The wind generating facility 100 includes a cluster of windturbines 101 installed on foundations at an offshore location. The windturbines 101 produce AC power which is transmitted along a line 110. AnAC-to-DC convertor is near the wind turbines 101 in order convert the ACpower into high voltage direct current (HVDC) for transmission to shore.The converter is a modular HVDC platform 104 which contains necessaryequipment to convert the AC to HVDC for transmission to shore via atransmission line 112. The HVDC line is supported on an optional modulesupport frame 113. The transmission line 112 may cover a great length,such as tens or hundreds of miles, before reaching shore. The HVDC isconverted again to AC at an inverting station 105 where it isdistributed into the distribution system 111 for consumption.

FIG. 2 is an isometric view of a modular HVDC platform 204 according toone embodiment. The modular HVDC platform 204 may be used in place ofthe modular HVDC platform 104 shown in FIG. 1. The modular HVDC platform204 has a structural jacket 203 supporting a topside 202. The structuraljacket 203 is a designed structure which is installed at the platformsite separately from the topside 202. Here, the structural jacket 203 isa pile system which is mounted on the seafloor. However, it is alsocontemplated that other designs of the structural jacket 203, such ascompliant towers, concrete gravity structures, jack-up vessels, or evenfloating structures can be utilized with the embodiments describedherein. The structural jacket 203 provides adequate support for thetopside 202 and the associated HVDC equipment described below. Thejacket 203 may be secured using hammered or drilled piles, or othersecuring devices. It is contemplated that the use of drilled pilesreduces the total number of piles necessary for securing the jacket dueto the greater depth in to which drilled piles are disposed, compared tohammered piles. Moreover, drilled piles obviate the need for bubblecurtains (and studies associated therewith), further reducing costswhile also mitigating high noise levels typically associated withhammered piles.

The topside 202 is formed from three modular sections includingrectifier modules 206 a, 206 b, and a utility module 208. The rectifiermodules 206 a, 206 b are positioned at opposite ends of the structuraljacket 203 with the utility module 208 disposed therebetween.Connections and couplings, such as electrical cables, hoses, opticalfibers, and the like, are disposed therebetween to facilitateelectrical, fluid, or other connections between the rectifier modules206 a, 206 b, and the utility module 208. In one example, the rectifiermodules 206 a, 206 b are identical to one another. In another example,the rectifier modules 206 a, 206 b mirror one another.

Each rectifier module 206 a, 206 b includes equipment to supportconversion of AC power to DC power. Exemplary equipment includesrectifiers, reactors, switch gear, monitoring equipment, safetyequipment (such as fire protection), and cooling systems, among others.Each rectifier module 206 a, 206 b is configured to convert the positivenode or the negative node of the AC power. Therefore, a module forconverting both positive and negative nodes is provided. The illustratedconfiguration (e.g., the utility module 208 positioned between therectifier modules 206 a, 206 b) reduces the length of couplings betweenthe utility module 208 and each of the rectifier modules 206 a, 206 b.However, it is contemplated that other configurations, such aspositioning the rectifier modules 206 a, 206 b adjacent one another, mayalso be utilized.

Each rectifier module 206 a, 206 b includes a housing 207 in which theequipment is housed. Each housing 207 is formed from stressed steelskin, such as corrugated stainless steel, or another alloy, whichresults in increased rigidity and reduced weight of each housing 207.The stressed steel skin results in a weight reduction of about 15percent over the architectural cladding of conventional structures.Optional corrugation of the skin imparts additional rigidity. Eachhousing 207 may also include a frame 221 (shown partially, in phantom)or other structure to facilitate support of the stressed steel skin onoutward surfaces of the frame 221. Although only rectifier module 206 bis shown with a frame 221, it is to be understood that the housings 207of the rectifier module 206 a and the utility module 208 may also haveframes 221.

Each housing 207 includes four sidewalls and optionally a roof. Eachrespective housing 207 allows the rectifier modules 206 a, 206 b and theutility module 208 to be constructed independently, while the equipmenttherein remains protected, for example, while stored at a facility.Thus, the rectifier modules 206 a, 206 b and the utility module 208 canbe constructed and commissioned independently at separate locations or aseparate times, facilitating inexpensive construction. For example,aspects herein may lead to a reduction in capital expenditure of about10 percent compared to conventional topsides having equivalent operatingperformance. Moreover, since the rectifier modules 206 a, 206 b and theutility module 208 can be constructed and stored, such modules may bepre-fabricated prior to commissioning of a HVDC platform, therebyreducing the construction time for a HVDC platforms.

The housings 207 also facilitate a controlled environment which may bemore easily temperature-controlled, as compared to conventional designs.The relatively small volume within each housing 207 is more easilymaintained within a desired operating temperature range byheating/cooling equipment. Therefore, equipment within each housing 207can be positioned in closer proximity without overheating, thus reducingthe volume of each housing 207. In contrast, in conventional designs,such as those employing a single, non-modular topside, temperaturecontrol is more challenging. Thus, in conventional designs, operatingequipment is spaced further apart compared to aspects disclosed hereinin order to mitigate the likelihood of adjacent components overheatingdue to radiating energy of the adjacent components.

The utility module 208 is disposed between, and coupled to (electricallyand/or physically), the rectifier modules 206 a, 206 b. In one example,a gap or walkway 209 is positioned between the utility module 208 andeach rectifier module 206 a, 206 b to facilitate access therebetween.The walkway 209 may have a width in within a range of two meters toabout three meters, although other widths are also contemplated. Theutility module 208 also includes a housing 207 and contains equipmenttherein to support the HVDC conversion operations of the rectifiermodules 206 a, 206 b as well as electrical systems for transmittingpower. The utility module 208 also functions as the incoming/outgoingcable termination and distribution connection for the modular HVDCplatform 204. Exemplary equipment used in the utility module 208includes AC transformers, reactors, switchgear (such as for 400 KV, 155KV, 10 KV, 400V, and 220V), seawater lift systems, cooling heatexchangers, control room and associated control systems, fire monitoringand protection equipment, and emergency generators, among others.

In one example, the utility module 208 is configured to support one ormore auxiliary units 250 on an upper surface 225 (e.g., roof) of therespective housing 207. The one or more auxiliary units 250 includeadditional equipment or storage. For example, the one or more auxiliaryunits 250 may include an emergency generator, generator switchgear, agarbage room or other garbage storage, hazardous material storage,and/or one or more cranes. In one example, two cranes are positioned atopposing corners of the upper surface 225. Positioning the auxiliaryunits 250 on the utility module 208 facilitates even weight distributionand efficient floor space usage amongst the topside 250. While the roof250 is shown as a continuous roof across all modules, it is contemplatedthat each module may include a separate roof discontinuous from roofs ofother modules (such that walkways 209 are exposed or partially exposed).Alternatively, each module may include a distinct, respective sub-roofunder the upper surface 225.

In some examples, the utility module 208 and the rectifier modules 206a, 206 b may each include therein a plurality of sublevels 230 (two areshown in the utility module 208) to facilitate equipment placement,maintenance, and the like. In a specific example, the utility module 208includes a plurality of sublevels 230 therein, such as two sublevels230, while each of the rectifier modules 206 a, 206 b includes a singlesublevel 230. In such an example, the sublevels 230 of the utilitymodule 208 have a length (y-direction) and width (x-direction) spanningthe interior volume of a respective housing 207. The sublevels 230 ofthe rectifier modules 206 a, 206 b have a width spanning a respectivehousing 207 interior width, but a length less than a respective housing207 length, such as a length of about 40 percent to about 60 percent ofa length of the respective housing 207. A continuous roof structure maybe positioned over each of the utility module 208 and the rectifiermodules 206 a, 206 b to facilitate protection from the elements. In suchan example, it is contemplated that the continuous roof structure isformed from a plurality of adjoining panels, and overhangs or is alignedwith the perimeter of the topside 202.

In one example, the utility module 208 may have a weight within a rangeof about 5500 MT to about 7500 MT, such as about 7100 MT. Each rectifiermodule 206 a, 206 b may have a weight within a range of about 3200 MT toabout 5000 MT, such as about 4100 MT. In one example, including amodular support and connections and couplings between the utility module208 and the rectifier modules 206 a, 206 b, the topside 202 has a weightwithin a range of about 14,500 MT to about 15,500 MT, providing asignificant weight savings over conventional topsides. In one example,the weight of the topside 202 is about 15 percent to about 30 percentless than conventional topsides, having equal operational performance.Moreover, the reduction in weight of the topside 202 compared toconventional topsides increases the availability of vessels fortransporting the topside 202 to the structural jacket 203, because morevessels having the lifting capacity for transporting/positioning thetopside 202 become available due to the reduced weight. By arranging theHVDC equipment into the utility module 208 and the rectifier modules 206a, 206 b, the ability to control the temperature of equipment isimproved. Thus, reduced layouts can be utilized, compared toconventional topsides, resulting in weight savings over previousapproaches.

FIG. 3 is a schematic arrangement, in plan, of the topside 202 of themodular HVDC platform 204 (shown in FIG. 2). Each rectifier module 206a, 206 b has a rectifier hall 344 and a reactor hall 346. Rectifiers 342are disposed within the rectifier halls 344. Here, three rectifiers 342are representatively shown in each rectifier hall 344. However, othersuitable numbers of rectifiers 342 suitable for converting the AC powerto DC power may be used in relation to the generating capacity of thesite. Adjacent to the rectifier halls 344 are reactor halls 346. Thereactor halls 346 contain reactors 348 therein. The reactors 348 are,for example, smoothing reactors, filter reactors, or other suitablefilters for HVDC operations.

A utility block 350 is also disposed with the rectifier modules 206 a,206 b. The utility blocks 350 each include one or more utility systems,such as heating and cooling systems, fire monitoring and protectionsystem, as well as the control room and control systems, among othercomponents, that are associated with supporting the operation of therectifiers 342 and the reactors 348. In one example, each rectifiermodule 206 a, 206 b includes a respective control system in a utilityblock 350. Thus, each rectifier module 206 a, 206 b can be fabricatedand tested prior to installation and commissioning, even at differentlocations. The ability to fabricate and test the rectifier modules 206a, 206 b individually increases the number of fabrication site options,allowing lower cost construction and faster schedules to be obtained.

In one example, the reactor hall 346 is positioned on a level above theutility block 350. In such an example, space usage within the rectifiermodules 206 a, 206 b is optimized, and the volumes thereof minimized.Further, the reactor hall 346 is positioned laterally from the rectifierhall 344. Lateral placement of the reactor hall 346 relative to therectifier hall 344 results in a reduced height (and a correspondingreduced volume) of the rectifier modules 206 a, 206 b. Moreover, thereduced height (z-direction, FIG. 2) of the rectifier modules 206 a, 206b results in reduced structural components (such as framing material andskins of a respective housing), thereby resulting in further reductionsof weight and cost of the topside 202. Conventionally, reactor halls andrectifier halls are positioned vertically over one another to reduce thetopside footprint. However, it has been surprisingly discovered thatweight savings attributable to horizontal placement of the reactor hall346 relative to the rectifier hall 344 (facilitated, in part, byincreased temperature control capacity of each rectifier module 206 a,206 b due to the reduced volume therein) results in greater weightreduction than vertical placement of the reactor hall 346 relative tothe rectifier hall 344. In such an example, the reactor 348 of thereactor hall 346 may be positioned coplanar (e.g., horizontal) withrespect to the rectifiers 342 of the rectifier hall 344.

The utility module 208 is coupled to the rectifier modules 206 a, 206 bby one or more connecting members 335. The connecting members includeone or more electrical, fluid, or mechanical connections, includingwiring, piping, fiber optics, and the like. The utility module 208contains equipment for supporting the operations of the rectifiermodules 206 a, 206 b. A cable termination 320 is disposed within theutility module 208. The cable termination 320 functions as the entry andexit location for the cables for transmitting the generated power fromthe turbines. A first plurality cables provide the AC power from theturbines to the topside 202. After conversion from AC power to DC power,a second plurality of cables transmits the DC power from the topside 202to a destination, such as a land-based invertor station, for joininginto the distribution network.

The utility module 208 also contains transformers 322. The transformerscan be AC and/or DC transformers for increasing and/or decreasingvoltage as needed. Switchgear 328 is utilized in the utility module 208.The switchgear 328 represents systems, relays, and disconnects for bothAC power and DC power to control the flow of each. The utility module208 also contains a utility block 324. The utility block 324 representsthe utility systems for supporting the utility module 208 and therectifier modules 206 a, 206 b. The utility block 324 includes one ormore of panels and control systems for the HVDC system, cooling andheating systems, sea water pumping systems, water circulation systems,fire monitoring and protection systems, control rooms, maintenanceworkshops, and storage space, among other components.

FIG. 4 is a block diagram representing current flow through an HVDCsystem 400 of the modular HVDC platform 204. The block diagram begins ata cable termination 320. AC power enters the modular HVDC platform 204at the cable termination 320 and flows to the 155 KV switchgear 328.From the 155 KV switchgear 328, the AC power is split between two blocksof transformers 322 which step the voltage up to 400 KV. The AC powerthen flows to the 400 KV switchgear 458 before being directed torectifier banks. A first rectifier bank 442 a corresponds to thepositive node of the AC power. A second rectifier bank 442 b correspondsto the negative node of the AC power. The AC power is converted to DCpower in the rectifier banks 442 a, 442 b.

After conversion, the DC power flows through a series of reactors 348.The reactors 348 are, for example, smoothing reactors which reduce theharmonics generated by the cyclic current of the AC power. After thereactors 348, the DC power returns to the cable termination 320. The DCpower exits the modular HVDC platform 204 at the cable termination 320through transmission cables to be transmitted to land for use in adistribution network. The cable termination 320 serves as a common entryand exit point for the AC power and DC power. However, the cabletermination 320 is divided so that the AC power and the DC power do notcome into contact. Alternatively, it is contemplated distinct entry andexits points may be utilized to further reduce the likelihood ofgenerating an electrical short. While FIG. 4 is described with respectto example voltages, it is contemplated that aspects herein may beutilized with other voltages.

By utilizing the HVDC system 400, the size and weight of the topside 202of the modular HVDC platform 204 can be significantly reduced, such asto a weight of about 14,500 to 16,000 metric tons. Conventional HVDCsystems utilize reactors positioned directly below rectifiers. However,the disclosure herein utilizes reactors in line (e.g., coplanar) withrectifiers and positioned laterally/horizontally therefrom. Therefore,the vertical space needed for housing the reactor halls and therectifier halls is significantly reduced. Additionally, aspectsdisclosed herein utilize modular construction. That is, the rectifiermodules 206 a, 206 b and the utility module 208 are constructed andcommissioned as separate modules. For example, the rectifier modules 206a, 206 b can be fabricated and fitted with most or all the HVDCequipment and control systems at a land-based yard. The equipment withinthe rectifier modules 206 a, 206 b can be pre-installed and tested priorto transportation of the module to the location of, and installation on,the structural jacket 203. The same is also done for the utility module208.

Upon installation of the rectifier modules 206 a, 206 b and the utilitymodule 208 onto the structural jacket 203, any remaining connections,such as fluid and adjoining electrical tie-ins, are made at theinstallation site. Thus, the construction costs are significantlyreduced since pre-fabrication and commissioning can be done on land atlocation and using techniques that are more cost effective thanconventional at-sea techniques. Further, the smaller size and weight ofthe rectifier modules 206 a, 206 b and the utility module 208 allow forsmaller and more readily available cranes for installation thereof ontothe structural jacket 203.

FIG. 5 is a flowchart of a method 500 of constructing an HVDC platform.The method 500 begins at operation 502. In operation 502, a substructureis installed. The substructure is, for example, the structural jacket203 of FIG. 2. In one example, the substructure can be fabricated at ayard and transported to the installation site such as by a heavy liftvessel (HLV). In another example, the substructure is fabricated andinstalled onsite. The substructure may have an optional module supportframe 113 (shown in FIG. 1) positioned thereon. The module support framefacilitates support and alignment of modules positioned thereon. Theoptional module support frame may be coupled to the substructure priorto transport to an offshore location, or may be coupled to thesubstructure at an offshore location. The module support frame mayinclude one or more tracks, receptacles, couplings, and the like forsecuring and aligning modules thereto. In one example, the modulesupport structure is a metal frame formed, for example, from I-beams. Inanother example, the module support structure is a truss structure. Inyet another example, the module support structure is a deck includingframe and an optional covering layer.

At operation 504, a first module is installed on the substructure, andin particular, on the module support frame, if present. The module maybe, for example, the utility module 208 or one of the rectifier modules206 a, 206 b. In one example, the first module is fabricated andpre-commissioned at a fabrication yard. The first module is thentransported to a location of the substructure and installed thereon. Inanother embodiment, the first module is fabricated at a first yard,transported to a second yard for installation of equipment,commissioning, and/or testing, and then transported to the site of thesubstructure for installation. A crane may be used to position the firstmodule on the substructure, at either a central position or alaterally-outward position on the substructure. One or more alignmentfeatures may be include on the first module and/or the substructure (oroptionally, the modular support frame) to facilitate alignment orsupport when positioning the first module over the substructure. In oneexample, the alignment features include a plurality of male/femaleadapters.

At operation 506, a second module used is installed on the substructure,and in particular, is installed on the module support frame, if present.The second module may be similar to the first module or a differentmodule type, and may be installed in similar manner to the first module.The installation of the second module may be repeated as needed toinstall one or more additional second modules to form the topside. Inone example, the operation 506 is repeated one additional time,resulting in three total modules positioned on the substrate structure.While embodiments herein describe placement of three modules on asubstructure, it is contemplated that installation may include more thanthree modules positioned on the substructure. It is contemplated thatthe second module may be transported to the structural jacket locationat a different time or on a different vessel than the first module.Additionally, it is contemplated that the first module and the secondmodule may be transported to a location of the structural jacket on thesame vessel, size permitting.

At operation 508, the coupling of the topside, including the adjoiningof modules together and to the substructure, is completed. For example,connections between the first and second modules, such as coolingsystems, electrical connections, control systems, and the like, aremade. Any remaining commissioning tasks are also completed at this time.

While embodiments herein describe topsides including a single modulesupport frame and three modules disposed therein, other configurationsare also contemplated. For example, it is contemplated that topsidesdisclosed herein may be scaled to handle greater power requirements, orfor distribution to different locations. In one example, a topsideincludes multiple utility modules, and two or more rectifier modules perutility module. In another example, a substructure, such as jacket 203,supports a plurality of module support frames, such as module supportframe 113, shown in FIG. 1. In such an example, each module supportframe supports at least one utility module and at least one or morerectifier modules. In yet another example, it is contemplated that aplurality of HVDC modular platforms may be arranged adjacent oneanother, and may be operatively coupled. Such an arrangement facilitatesease of maintenance on the HVDC modular platforms due to the relativelyclose proximity therebetween.

The embodiments herein advantageously provide a modular HVDC platformand a method for constructing the same. By utilizing the modular design,the overall size and weight of the HVDC platform is significantlyreduced. The reduced size and weight of the modular units allows forjacket of reduced size to be utilized, further reducing capitalexpenditure. Costs of construction for the modular units are alsosignificantly reduced by the embodiments described herein. The modulardesign allows for fabrication and pre-commissioning of significantportions of the HVDC system to be completed in a fabrication yard priorto transportation of a module to an install site. Additionally, thecrane size and capacity used to install the topside onto a substructureand to perform maintenance on the HVDC system is greatly reduced.Therefore, less expensive and more readily available lifting vessels canbe used to construct and maintain the modular HVDC platform.

Moreover, connections between various components and equipment of thedisclosed topside are also simplified, thereby reducing thecommissioning schedule and resulting in cost savings. Connections mayinclude, for example, electrical and fluid conduits, such as plumbing,HVAC, pipes, hoses, and the like. During fabrication of each module,e.g., the utility module and the rectifier modules, at an onshorefabrication yard, electrical and fluid conduits may be placed therein indesired locations. Once transported to the offshore jacket and movedinto position, connections between fluid and electrical conduits of theutility module and the rectifier modules may be easily made via easilyaccessible connection points of each housing. In such a manner, amajority of conduits are already installed and merely need to beconnected via the easily accessible connection points. The easilyaccessible connection points may be presented at a location adjacent aconnection point of a neighboring module, thereby reducing the distancefor routing a connecting member therebetween. The relatively shorterconnecting members are easy for operators to manage and inexpensive toinstall.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

What is claimed is:
 1. An offshore platform for power generation,comprising: a structural jacket; a utility module disposed on thestructural jacket, the utility module disposed in a first housing; andone or more rectifier modules disposed on the structural jacket adjacentto the utility module, each of the one or more rectifier modulesdisposed in a respective second housing, each rectifier modulecomprising equipment for converting AC power to DC power.
 2. Theplatform of claim 1, wherein the utility module and the one or morerectifier modules are supported on a module support frame positioned onthe structural jacket.
 3. The platform of claim 1, wherein the one ormore rectifier modules are commissioned at a first onshore locationprior to installation onto the structural jacket at an offshorelocation.
 4. The platform of claim 3, wherein the utility module iscommissioned at a second onshore location prior to installation onto thestructural jacket at an offshore location.
 5. The platform of claim 1,wherein the equipment for converting AC power to DC power comprises: oneor more rectifiers in a rectifier hall; and one or more reactors in areactor hall.
 6. The platform of claim 5, wherein the rectifier hall ispositioned laterally from the reactor hall.
 7. The platform of claim 1,wherein the housing comprises corrugated stressed steel skin.
 8. Theplatform of claim 7, wherein a first rectifier module of the one or morerectifier modules corresponds to a positive node of AC power and asecond rectifier module of the one or more rectifier modules correspondsto a negative node of AC power.
 9. A system for wind energy generation,comprising: an offshore platform comprising a structural jacket and atopside, wherein the topside comprises a plurality of modular sectionsposition on a module support frame; a first plurality of rectifiersdisposed in a first module of the plurality of modular sections, thefirst module positioned within a first housing; a second plurality ofrectifiers disposed in a second module of the plurality of modularsections, the second module positioned within a second housing; and athird module of the plurality of the modular sections, wherein the thirdmodule is a utility module configured to support the operations of thefirst module and the second module, the third module positioned within athird housing.
 10. The system of claim 9, wherein third module ispositioned between the first module and the second module on the modulesupport frame.
 11. The system of claim 9, wherein the first housing, thesecond housing, and the third housing each comprise a frame having asteel skin coupled to outer surfaces thereof.
 12. The system of claim 9,wherein the first module further comprise a plurality of reactors,wherein the plurality of rectifiers are disposed in a rectifier hall andthe plurality of reactors are disposed in a reactor hall, the reactorhall positioned laterally from the rectifier hall.
 13. The system ofclaim 9, wherein the first module comprises a first utility block, thefirst utility block comprising a heating and cooling system and acontrol system for facilitating operation of the first module, andwherein the second module comprises a second utility block, the secondutility block comprising a heating and cooling system and a controlsystem for facilitating operation of the second module.
 14. The systemof claim 9, wherein both the first module and the second module areconfigured to convert AC power to DC power, wherein the first modulecorresponds to a positive node of AC power and the second modulecorresponds to a negative node of AC power.
 15. A method of constructingan offshore platform, comprising: installing a substructure at anoffshore location; installing a module support frame on thesubstructure; installing a first module of a topside on the modulesupport frame, the first module comprising pre-installed equipment forconverting AC power to DC power; installing a second module of thetopside on the module support frame, the second module comprisingpre-installed equipment for converting AC power to DC power; andcoupling the first module and the second module.
 16. The method of claim15, further comprising installing an additional second module on themodule support frame, wherein the first module is positioned between thesecond module and the additional second module.
 17. The method of claim16, wherein the equipment for converting AC power to DC power in thefirst module and the second module is commissioned prior to installingthe first module and second module on the module support frame.
 18. Themethod of claim 16, wherein: the second module comprises a first controlsystem, a first heating and cooling system, and a first rectifier hallpositioned laterally from a first reactor halls; and the additionalsecond module comprises a second control system, a second heating andcooling system, and a second rectifier hall positioned laterally from asecond reactor hall.
 19. The method of claim 15, wherein the couplingcomprises forming one or more electrical or fluid connections betweenthe first module and the second module.
 20. The method of claim 15,wherein the first module and the second module are constructed onshoreand transported to the offshore location on separate vessels.